したがって、ファイルに保存する必要があるオブジェクトの NSMutableArray があります。writeToFileこのメソッドが生成する .plist 形式では許可されていない NSNull 値があるため、メソッドで保存することはできません。
したがって、ファイルを NSString として保存することで、ファイルをディスクに保存しています。
NSString *content = [NSString stringWithFormat:@"%@",orders];
[content writeToFile:ordersFilePath atomically:NO];
次のようなファイルが生成されます。
(
        {
        ZBILLINGADDRESS1 = "";
        ZBILLINGADDRESS2 = "";
        ZBILLINGCITY = "";
        ZBILLINGCOUNTRY = "";
        ZBILLINGSTATE = "";
        ZBILLINGZIP = "";
        ZCANCELDATE = "<null>";
        ZCATALOGCODE = "";
        ZCATALOGNAME = "";
        ZCONTACTEMAIL = "";
        ZCONTACTFAX = "";
        ZCONTACTNAME = " ";
        ZCONTACTPHONE = "";
        ZCONTAINERCUBES = 0;
        ZCONTAINERNAME = "";
        ZCURRENCYCODE = "<null>";
        ZCUSTOMERID = 0;
        ZCUSTOMERNAME = "Dupe offline Test";
        ZCUSTOMERNUMBER = 1297145;
        ZDISCOUNT = 0;
        ZDONOTSHIPBEFORE = "<null>";
        ZEXPORTDATE = "-63113886238";
        ZEXPORTED = 1;
        ZFOB = "";
        ZFREIGHTTERM = "";
        ZISCONTAINER = 0;
        ZISDEFAULT = 0;
        ZISDELETED = 0;
        ZISPLACED = 0;
        ZMANUFACTURERID = 18;
        ZMARKETNAME = "";
        ZNOTES = "last second note";
        ZORDERDATE = 372571200;
        ZORDERGUID = "5650d30a-9316-436a-87e9-1e0ead3af8d7";
        ZORDERID = 84340;
        ZORDERSTATUS = Accept;
        ZORDERTOTAL = 200;
        ZORDERTYPE = "";
        ZORIGIN = "";
        ZPONUMBER = 3;
        ZPRICELEVEL = 2;
        ZREPNUMBER = 1;
        ZSALESREPID = 235;
        ZSHIPDATE = 373176000;
        ZSHIPPINGTOTAL = 0;
        ZSHIPTOADDRESS1 = "";
        ZSHIPTOADDRESS2 = "";
        ZSHIPTOCITY = "";
        ZSHIPTOCOMPANYNAME = "";
        ZSHIPTOCONTACTEMAIL = "";
        ZSHIPTOCONTACTNAME = "";
        ZSHIPTOCONTACTPHONE = "";
        ZSHIPTOCOUNTRY = "";
        ZSHIPTOFAX = "";
        ZSHIPTOSTATE = "";
        ZSHIPTOZIP = "";
        ZSHIPVIA = "";
        ZSOURCE = ipad;
        ZSUBTOTAL = 200;
        ZTAXRATE = 0;
        ZTAXTOTAL = 0;
        ZTERMS = "";
        ZWRITTENBYNAME = "";
        ZWRITTENFORNAME = "";
        ZWRITTENFORREPNUMBER = "";
        ZWRITTENFORREPNUMBER1 = "<null>";
        "Z_ENT" = 17;
        "Z_OPT" = 5;
        "Z_PK" = 450;
    }
)
問題は、これを NSArray としてリロードしようとすると、null 値が返されることです。
NSString *str = [NSString stringWithContentsOfFile:ordersFilePath encoding:NSUTF8StringEncoding error:NULL];
    NSArray *loadedOrders = [[NSArray alloc] initWithContentsOfFile:str];
ここで何が欠けていますか?